Technical Knowledge

What are the analog and switch values in servo control?
Release Date : 2021-07-03 17:35:11



In the control system, a common term is analog quantity and switch quantity. Regardless of input or output, a parameter is either an analog or a switch.
 
 
The analog quantity refers to the size of the control system quantity is a continuous value that changes within a certain range, such as temperature from 0 to 100 degrees, pressure from 0 to 10 MPA, liquid level from 1 to 5 meters, and electric valve opening from 0 to 100 %, etc. These quantities are all analog quantities.
 
 
 
Analog quantity is a continuously changing physical quantity, such as voltage, temperature, pressure and speed. The PLC cannot directly process the analog quantity. It needs the A/D converter in the analog quantity input module to convert the analog quantity into a digital quantity proportional to the input signal for use by external actuators (such as electric control valves or inverters).
 
 
 
The switch value includes binary input and binary output. It is a digital signal with only two states of "0" and "1".
 
 
 
The binary input comes from a contact outside the protection device for use by the protection device. The opening amount is the contact provided by the protection device to the outside, which is supplied to the external equipment, such as the on/off state of the switch, the closing/opening of the relay, the on/off of the solenoid valve, and so on. PLC can directly input and output switch signals.
 

Connection diagram of traditional servo motor





 

NIMOTION integrated servo motor connection diagram




 

Main features of PMM series integrated servo motors:
 
 
1. Modular high-integration design, rapid site layout and installation, eliminating the need for matching process between the driver and the motor, reducing the cost of the field bus, and reducing the cost of use.
 
 
 
2. It is connected to the controller through the EtherCAT/CANOpen protocol (DS402), and each node directly uses hardware to implement calculations without software participation, which greatly reduces the message delay time. Transmission rate: 2x100Mbps (full duplex) The hardware delay of a servo axis is only 1us.
 
 
 
3. The control accuracy reaches ±1rpm and ±1pulse, with a real-time response period of 1ms, with excellent control performance and good positioning accuracy.